Hello everyone, SCIENSPOT is a podcast that shines a spotlight on the latest scientific technology from Japan. Your host is REN from SCIEN-TALK.
Today, we're dedicating this episode to a legend in the scientific world.
On January 9th, 2026, Kyoto University's Center for Evolutionary Origins of Human Behavior announced the passing of Ai, a female chimpanzee who changed history.
She was 49 years old.
Ai was not just an animal. She was a pioneer who helped us understand the origins of the human mind.
Led by Professor Tetsuro Matsuzawa, the Ai Project proved that chimpanzees could understand numbers, colors, and even kanji characters.
The most shocking discovery came not from what Ai could do like humans, but what she and her son Ayumu could do better than humans.
This is known as the masking task.
Imagine numbers 1 through 9 flashing on screen for just 0.2 seconds before being covered by white squares.
Could you remember where each number was that tapped them in order?
For humans, this is physically impossible because our eyes cannot scan the screen fast enough.
Our accuracy drops below 40%.
But Ayumu, he can do this with 80% accuracy.
Chimpanzees possess something called aeditic imagery, a photographic memory that allows them to capture a detailed image of a scene instantly.
Why are they better than us?
Professor Matsuzawa proposed the cognitive trade-off hypothesis.
The theory suggests that the brain has limited space.
During evolution, humans developed language to cooperate and share complex information.
To make room for the brain function required for language, humans may have trade-off or suppress the ancient ability of instant photographic memory.
Chimpanzees living in a jungle where split-second decisions mean life or death kept this memory.
On the other hand, we chose words over speed.
We aren't superior, we just took a different evolutionary path.
Just before I passed away, a study published in November 2024 revealed the audience effect in chimpanzees.
It showed that like humans, chimpanzees perform better on difficult tasks when they're being just watched by others.
This proves they have a social awareness similar to ours.
I told her that intelligence comes in many forms.
She bridged the gap between us and our closet relatives.
These research results are really fascinating for us and I would say rest in peace.
In my podcast, Scientalk, we have talked about the many results of research on chimpanzees' awareness
and also discussed many topics about human nature and what we should do.
From the perspective of the difference between humans and chimpanzees,
this difference is very crucial for understanding ourselves.
So now I want to keep an eye on these researches in the future.
That's all for today's SciencePod.
This podcast is broadcast in both Japanese and English.
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Thank you for listening and see you next time.